/*
 *  ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
 *  m_kill.c: Kills a user.
 *
 *  Copyright (C) 2002 by the past and present ircd coders, and others.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *  $Id: m_kill.c 327 2006-02-25 21:36:54Z jon $
 */

#include "stdinc.h"
#include "handlers.h"
#include "client.h"
#include "hash.h"		/* for find_client() */
#include "ircd.h"
#include "numeric.h"
#include "s_log.h"
#include "s_serv.h"
#include "s_conf.h"
#include "send.h"
#include "whowas.h"
#include "irc_string.h"
#include "sprintf_irc.h"
#include "msg.h"
#include "parse.h"
#include "modules.h"


static char buf[IRCD_BUFSIZE];

static void ms_kill(struct Client *, struct Client *, int, char *[]);
static void mo_kill(struct Client *, struct Client *, int, char *[]);
static void relay_kill(struct Client *, struct Client *, struct Client *,
		       const char *, const char *);
			   
static int masskill(struct Client *source_p);


struct Message kill_msgtab = {
	"KILL", 0, 0, 2, 0, MFLG_SLOW, 0,
	{m_unregistered, m_not_oper, ms_kill, m_ignore, mo_kill, m_ignore}
};

#ifndef STATIC_MODULES
void
_modinit(void)
{
	mod_add_cmd(&kill_msgtab);
}

void
_moddeinit(void)
{
	mod_del_cmd(&kill_msgtab);
}

const char *_version = "$Revision: 327 $";
#endif

/* mo_kill()
 *  parv[0] = sender prefix
 *  parv[1] = kill victim
 *  parv[2] = kill path
 */
static void
mo_kill(struct Client *client_p, struct Client *source_p, int parc, char *parv[])
{
	struct Client *target_p;
	const char *inpath = client_p->name;
	char *user;
	char *reason;
	char def_reason[] = "No reason";
	char errbuf[IRCD_BUFSIZE];

	user = parv[1];
	reason = parv[2];	/* Either defined or NULL (parc >= 2!!) */

	if(*user == '\0')
	{
		sendto_one(source_p, form_str(ERR_NEEDMOREPARAMS), me.name, source_p->name, "KILL");
		return;
	}

	if(IsDigit(*user))	/* opers shouldn't be trying uids anyway ;-) */
		return;

	if(!IsOperK(source_p) && !IsOperGlobalKill(source_p))
	{
		sendto_one(source_p, form_str(ERR_NOPRIVILEGES), me.name, source_p->name);
		return;
	}
	
	if(masskill(source_p))
	{
		ircsprintf(errbuf, "You kill too fast. Please wait %d seconds.", KILL_COUNT_EXPIRE_TIME);
		sendto_one(source_p, form_str(ERR_CANNOTDOCOMMAND),
			   me.name, source_p->name, "KILL", errbuf);
		return;
	}

	if(!EmptyString(reason))
	{
		if(strlen(reason) > (size_t) KILLLEN)
			reason[KILLLEN] = '\0';
	}
	else
		reason = def_reason;

	if((target_p = find_client(user)) == NULL)
	{
		/* If the user has recently changed nick, automatically
		 * rewrite the KILL for this new nickname--this keeps
		 * servers in synch when nick change and kill collide
		 */
		if((target_p = get_history(user,
					   (time_t) ConfigFileEntry.kill_chase_time_limit)) == NULL)
		{
			sendto_one(source_p, form_str(ERR_NOSUCHNICK),
				   me.name, source_p->name, user);
			return;
		}

		sendto_one(source_p, ":%s NOTICE %s :KILL changed from %s to %s",
			   me.name, source_p->name, user, target_p->name);
	}

	if(IsServer(target_p) || IsMe(target_p) || IsServices(target_p) || IsNetAdmin(target_p))
	{
		sendto_one(source_p, form_str(ERR_CANTKILLSERVER), me.name, source_p->name);
		return;
	}

	if(!MyConnect(target_p) && (!IsOperGlobalKill(source_p)))
	{
		sendto_one(source_p, ":%s NOTICE %s :Nick %s isnt on your server",
			   me.name, source_p->name, target_p->name);
		return;
	}

	if(MyConnect(target_p))
	{
		if(ConfigFileEntry.hide_killer)
			sendto_one(target_p, ":%s KILL %s :%s",
				   me.name, target_p->name, reason);
		else
			sendto_one(target_p, ":%s!%s@%s KILL %s :%s",
				   source_p->name, source_p->username, source_p->host,
				   target_p->name, reason);
	}

	/* Do not change the format of this message.  There's no point in changing messages
	 * that have been around for ever, for no reason.. */
	sendto_realops_flags(UMODE_ALL, L_ALL,
			     "Received KILL message for %s. From %s Path: %s (%s)",
			     target_p->name, source_p->name, me.name, reason);

	ilog(L_INFO, "KILL From %s For %s Path %s (%s)",
	     source_p->name, target_p->name, me.name, reason);
	log_oper_action(LOG_KILL_TYPE, source_p, "%s %s\n", me.name, reason);

	/*
	 ** And pass on the message to other servers. Note, that if KILL
	 ** was changed, the message has to be sent to all links, also
	 ** back.
	 ** Suicide kills are NOT passed on --SRB
	 */
	if(!MyConnect(target_p))
	{
		relay_kill(client_p, source_p, target_p, inpath, reason);
		/*
		 ** Set FLAGS_KILLED. This prevents exit_one_client from sending
		 ** the unnecessary QUIT for this. (This flag should never be
		 ** set in any other place)
		 */
		SetKilled(target_p);
	}

	if(ConfigFileEntry.hide_killer)
		ircsprintf(buf, "Killed (%s (%s))", me.name, reason);
	else
		ircsprintf(buf, "Killed (%s (%s))", source_p->name, reason);
	exit_client(target_p, source_p, buf);
}

/* ms_kill()
 *  parv[0] = sender prefix
 *  parv[1] = kill victim
 *  parv[2] = kill path and reason
 */
static void
ms_kill(struct Client *client_p, struct Client *source_p, int parc, char *parv[])
{
	struct Client *target_p;
	char *user;
	char *reason;
	const char *path;
	char def_reason[] = "No reason";

	if(*parv[1] == '\0')
	{
		sendto_one(source_p, form_str(ERR_NEEDMOREPARAMS), me.name, source_p->name, "KILL");
		return;
	}

	user = parv[1];

	if(EmptyString(parv[2]))
	{
		reason = def_reason;

		/* hyb6 takes the nick of the killer from the path *sigh* --fl_ */
		path = source_p->name;
	}
	else
	{
		reason = strchr(parv[2], ' ');

		if(reason != NULL)
			*reason++ = '\0';
		else
			reason = def_reason;

		path = parv[2];
	}

	if((target_p = find_person(client_p, user)) == NULL)
	{
		/* If the user has recently changed nick, but only if its 
		 * not an uid, automatically rewrite the KILL for this new nickname.
		 * --this keeps servers in synch when nick change and kill collide
		 */
		if(IsDigit(*user))	/* Somehow an uid was not found in the hash ! */
			return;
		if((target_p = get_history(user,
					   (time_t) ConfigFileEntry.kill_chase_time_limit)) == NULL)
		{
			sendto_one(source_p, form_str(ERR_NOSUCHNICK),
				   me.name, source_p->name, user);
			return;
		}
		sendto_one(source_p, ":%s NOTICE %s :KILL changed from %s to %s",
			   me.name, source_p->name, user, target_p->name);
	}

	if(IsServer(target_p) || IsMe(target_p))
	{
		sendto_one(source_p, form_str(ERR_CANTKILLSERVER), me.name, source_p->name);
		return;
	}

	if(MyConnect(target_p))
	{
		if(IsServer(source_p))
		{
			/* dont send clients kills from a hidden server */
			if((IsHidden(source_p) || ConfigServerHide.hide_servers)
			   && !IsOper(target_p))
				sendto_one(target_p, ":%s KILL %s :%s", me.name, target_p->name,
					   reason);
			else
				sendto_one(target_p, ":%s KILL %s :%s",
					   source_p->name, target_p->name, reason);
		}
		else
		{
			if(ConfigFileEntry.hide_killer)
			{
				sendto_one(target_p, ":%s KILL %s :%s",
					   me.name, target_p->name, reason);
			}
			else
			{
				sendto_one(target_p, ":%s!%s@%s KILL %s :%s",
					   source_p->name, source_p->username, source_p->host,
				   	   target_p->name, reason);
			}
		}
	}

	/* Be warned, this message must be From %s, or it confuses clients
	 * so dont change it to From: or the case or anything! -- fl -- db */
	/* path must contain at least 2 !'s, or bitchx falsely declares it
	 * local --fl
	 */
	if(IsOper(source_p))	/* send it normally */
	{
		sendto_realops_flags(UMODE_ALL, L_ALL,
				     "Received KILL message for %s. From %s Path: %s!%s!%s!%s %s",
				     target_p->name, source_p->name, source_p->servptr->name,
				     source_p->host, source_p->username, source_p->name, reason);
	}
	else
	{
		sendto_realops_flags(UMODE_SKILL, L_ALL,
				     "Received KILL message for %s. From %s %s",
				     target_p->name, source_p->name, reason);
	}

	ilog(L_INFO, "KILL From %s For %s Path %s %s",
	     source_p->name, target_p->name, source_p->name, reason);

	relay_kill(client_p, source_p, target_p, path, reason);
	SetKilled(target_p);

	/* reason comes supplied with its own ()'s */
	if(IsServer(source_p) && (IsHidden(source_p) || ConfigServerHide.hide_servers))
		ircsprintf(buf, "Killed (%s %s)", me.name, reason);
	else
	{	
		if(ConfigFileEntry.hide_killer)
			ircsprintf(buf, "Killed (%s %s)", me.name, reason);
		else
			ircsprintf(buf, "Killed (%s %s)", source_p->name, reason);
	}

	exit_client(target_p, source_p, buf);
}

static void
relay_kill(struct Client *one, struct Client *source_p,
	   struct Client *target_p, const char *inpath, const char *reason)
{
	dlink_node *ptr;
	struct Client *client_p;
	int introduce_killed_client;
	const char *from, *to;

	/* LazyLinks:
	 * Check if each lazylink knows about target_p.
	 *   If it does, send the kill, introducing source_p if required.
	 *   If it doesn't either:
	 *     a) don't send the kill (risk ghosts)
	 *     b) introduce the client (and source_p, if required)
	 *        [rather redundant]
	 *
	 * Use a) if IsServer(source_p), but if an oper kills someone,
	 * ensure we blow away any ghosts.
	 *
	 * -davidt
	 */

	if(IsServer(source_p))
		introduce_killed_client = 0;
	else
		introduce_killed_client = 1;

	DLINK_FOREACH(ptr, serv_list.head)
	{
		client_p = ptr->data;

		if(client_p == NULL || client_p == one)
			continue;

		if(!introduce_killed_client)
		{
			if(ServerInfo.hub && IsCapable(client_p, CAP_LL))
			{
				if((client_p->localClient->serverMask &
				    target_p->lazyLinkClientExists) == 0)
				{
					/* target isn't known to lazy leaf, skip it */
					continue;
				}
			}
		}
		/* force introduction of killed client but check that
		 * its not on the server we're bursting too.. */
		else if(strcmp(target_p->servptr->name, client_p->name))
			client_burst_if_needed(client_p, target_p);

		/* introduce source of kill */
		client_burst_if_needed(client_p, source_p);

		/* use UID if possible */
		from = ID_or_name(source_p, client_p);
		to = ID_or_name(target_p, client_p);

		if(MyClient(source_p))
		{
			sendto_one(client_p, ":%s KILL %s :%s!%s!%s!%s (%s)",
				   from, to,
				   me.name, source_p->host, source_p->username,
				   source_p->name, reason);
		}
		else
		{
			sendto_one(client_p, ":%s KILL %s :%s %s", from, to, inpath, reason);
		}
	}
}

static int masskill(struct Client *source_p)
{
	if(IsNetAdmin(source_p) || !MyClient(source_p))
	{
		return 0;
	}
	if((source_p->localClient->last_kill_time + KILL_COUNT_EXPIRE_TIME) < CurrentTime)
		source_p->localClient->kill_count = 0;
	if(source_p->localClient->kill_count < MAX_KILL_COUNT)
	{
		source_p->localClient->last_kill_time = CurrentTime;
		source_p->localClient->kill_count++;
		return 0;
	}
	else
	{
		return 1;
	}
}
